JPH08145274A - Air-feed duct - Google Patents

Abstract

PURPOSE: To provide an air-feed duct which is constituted to reduce the generation of noise in relation to noise of the air-feed duct having frequency distribution differed with an installation state and a use state. CONSTITUTION: An air-feed duct comprises a cylindrical wall body 2a on the inner surface of which a sound absorbing plate 6 is mounted. The sound absorbing plate 6 comprises a pair of electrode plates positioned facing each other; an ENC fluid composition disposed between a pair of electrode plates and having EA particles contained in an electric insulation property medium; and a voltage application adjusting means 20 to apply a voltage between a pair of electrode plates and adjust a voltage.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air supply duct used for air conditioning equipment or various smoke exhaust devices, and more particularly to a low noise type which can suppress the leakage of noise to the outside. Regarding the air supply duct.

[0002]

As is well known, in the air supply duct,
Noise is generated by air supply. The frequency distribution of this noise varies depending on the installation status of the air supply duct. Further, this noise may also be caused by seasonal fluctuations in the amount of air supply, that is, fluctuations in the amount of air supply due to switching between air supply for cooling and heating, or fluctuations in the amount of air supply when the line is changed in the factory. The frequency distributions are different. Further, when the fan driving motor connected to the air supply duct is changed, the frequency distribution of noise from the motor transmitted to the air supply duct changes.
Alternatively, when the rotation speed of the fan driving motor is controlled by the inverter, the rotation speed of the motor sequentially changes, so that the noise frequency distribution changes sequentially.

Conventionally, for the purpose of reducing this noise, the cross section is rapidly enlarged in the middle of the lining duct lined with the conventional sound absorbing member made of porous plastic, glass wool, felt or the like, or the air supply duct, A cavity type silencer was used that attenuates the sound transmitted to the front of the air supply duct by the reflection of noise waves at the discontinuous boundary surface. Further, in JP-A-1-302060, as shown in FIG. 12, the resonance cylinders 1a, 1a are provided in the air supply duct 1.
There has been disclosed a technique for reducing noise by incorporating a fixed type.

[0004]

However, in the above-mentioned lined duct, the sound absorbing effect of the conventional lined sound absorbing member in the low frequency band is not sufficient, and the noise level cannot be sufficiently reduced. There was a problem. In addition, in the hollow silencer, in order to improve the attenuation value, the enlargement ratio of the cross section is increased (for example, several 10
However, there is a problem that it requires a large space because it is bulky. Further, there is a problem that the blowing efficiency is reduced due to the enlarged cross section. Moreover, there were cases where it could not be adopted due to space constraints. In addition, in the air supply duct 1, the frequency at which the sound can be silenced is the resonance tube 1
It depends on the shape of a. That is, since the frequency that can be silenced is determined at the time of manufacturing, the air supply duct 1 having a different frequency distribution depending on the installation condition and the use condition.
There is a problem that the actual noise cannot be reduced sufficiently because the frequency distribution of the actual noise is not flexible and the frequency distribution of the actual noise and the frequency component that can be muted by the resonance cylinder 1a are easily deviated. Further, since the resonance cylinder 1a is built in the air supply duct 1, the resonance cylinder 1a interferes with the air supply and lowers the air blowing efficiency.
Has a problem that the air supply duct 1 becomes large because the installation space is required, and the air supply direction is limited because one end of the resonance cylinder 1a is open, and the workability of the air supply duct 1 is poor. It was

By the way, the inventors of the present invention have proposed a novel electric field arrangement characteristic (Electric Alig) which has not been known in the past.
(hereinafter referred to as "EA characteristic" for short).
(hereinafter, referred to as “ENC fluid composition”, which is abbreviated as “lectric noise-control fluid composition”). This ENC fluid composition is, for example,
It is a fluid obtained by dispersing solid particles in an electrically insulating medium.When a voltage is applied to this, the solid particles cause dielectric polarization, and they are coordinately connected to each other in the electric field direction by electrostatic attraction based on the dielectric polarization. It has the property of being aligned and exhibiting a chain structure. In addition, some solid particles exhibit the property of exhibiting an array lump structure by electrophoresis and array alignment. The array orientation of particles under an electric field is called an electric field array effect (Electric Alignment effect for short, hereinafter referred to as “EA effect”), and solid particles having such a property are referred to as electric field array particles (Elect effect).
The ric Alignment particles are abbreviated as “E
It is referred to as "A particle"). Then, the present inventors arrived at the present invention by advancing research on the ENC fluid composition having this novel structure.

The present invention has been made in view of the above circumstances, and performs sound wave absorption control provided with an ENC fluid composition having an EA effect and capable of controlling the characteristic frequency by the applied voltage, and the installation situation and It is an object of the present invention to provide an air supply duct that can achieve low noise by efficiently absorbing the noise of the air supply duct whose frequency distribution varies depending on the usage situation.

[0007]

In order to solve the above problems, the present invention adopts the following configuration. That is, in the air supply duct of the present invention, it is constituted by a cylindrical wall body having an inner surface to which a sound absorbing plate is attached, and the sound absorbing plate is arranged between a pair of opposing electrode plates and between the pair of electrode plates. A fluid composition for electro-sensitive sound wave absorption control, which is provided and contains solid particles having an electric field array effect in an electrically insulating medium, and a voltage is applied between the pair of electrode plates and the voltage is adjusted. It is characterized in that it is provided with a voltage application adjusting means.

[0008]

In the air supply duct of the present invention, the sound absorbing plate comprises a pair of electrode plates, and EA particles having an EA effect which are arranged between the pair of electrode plates and are contained in an electrically insulating medium. The ENC fluid composition and a pair of electrode plates are provided with voltage application adjusting means for applying a voltage and adjusting the voltage. At this time, when no voltage is applied between the pair of electrode plates, E in the ENC fluid composition is
The EA particles having the A effect are randomly suspended and dispersed in the electrically insulating medium.

When a certain voltage is applied to the pair of electrode plates by the voltage application adjusting means, the EA particles are arranged and linked in a chain to form a chain (particle chain), which chain is oriented in the electric field direction. Arrange in parallel. When a sound wave (air vibration) is applied to one of the electrode plates in this state, the electrode plate vibrates in the direction opposite to these electrode plates, but the chain itself has elastic properties, so the chain When the body is pulled, the particles facing each other attract each other to generate an attractive force, and when it is compressed, it bends to generate a repulsive force, which causes viscous resistance due to the movement of the chain in the electrically insulating medium. This causes the energy loss (dissipation) of the sound waves.

That is, the ENC fluid composition containing a chain resonates with the electrode plate due to the sound wave incident on the electrode plate. The sound wave frequency that gives vibration to such a chain is determined by the characteristic frequency of the chain (which is presumed to be the so-called natural frequency, which is the balance between the elasticity of the chain and the inertia of the electrode plate). When a sound wave having a frequency matching the characteristic frequency is incident on the electrode plate, the chain resonates and absorbs the sound wave, and sound waves of other frequencies are reflected.

Since the attractive force (stress generated in the chain) acting between the particles increases as the voltage applied to the pair of electrode plates increases, the elastic modulus and viscosity of the chain itself are applied. The present invention takes advantage of this as the voltage increases as the voltage increases. In other words, the applied voltage is adjusted so that the characteristic frequency of the chain itself matches the frequency component of the incident sound wave (air vibration) to be removed, so that the chain resonates and absorbs (removes) sound. ) It consumes the energy of the desired component and reflects the other components.

FIG. 9 is a graph showing the results of measuring the effect of the electric field strength on the EA characteristics for the EA particle 30 wt% dispersion system. It is clear from this graph that the stress acting on the chain increases as the applied voltage increases. EA
The characteristic is that the dielectrically polarized particles are arranged in the direction of the electric field by an electric attraction to form a chain structure. At low shear rates, electrical attraction dominates, resulting in a gradual cycle of breaking and reforming chain structures. The yield stress is the force that is generated when a chain arranged in the direction of the electric field undergoes shear failure in the direction perpendicular to it. Considering that the particles of all the chains formed have the same diameter and connect the electrode plates in a straight line, the number of chains is proportional to the particle concentration.
The yield stress will also be proportional to the particle concentration. Figure 10
The equivalent circuit of the vibration at this time is shown, and the elastic modulus K
It is shown that the coil spring and the dashpot having the viscosity C are equivalent to those connected in parallel between the pair of electrode plates.

Therefore, by adjusting the applied voltage by the voltage application adjusting means, the characteristic frequency of the chain itself can be matched with the frequency component of the incident sound wave (air vibration) to be removed. Then, the chain resonates with the sound wave of the frequency component to be removed, consumes the energy of the sound wave, and reflects the sound wave of other components. Therefore, according to the air supply duct of the present invention, by adjusting the applied voltage, the frequency distribution of the noise that is actually observed with respect to the noise of the air supply duct whose frequency distribution differs depending on the installation condition and the use condition. The sound absorption range of the sound absorbing plate is selected in accordance with the above, and noise can be reduced by absorbing the noise by this sound absorbing plate.

[0014]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of the air supply duct of the present invention. Reference numeral 2 is an air supply duct, 2a is a cylindrical wall body that constitutes the air supply duct 2, and side wall bodies 3 and 3 are provided. The upper wall body 4 and the lower wall body 5 form a rectangular cross section. The area surrounded by the cylindrical wall 2a forms an air supply space. At this time, the sound absorbing plates 6, 6 are attached to the inner surfaces of the side wall bodies 3, 3.

As shown in FIG. 2, the sound absorbing plate 6 is divided into a plurality of sound absorbing portions 6a, 6a. The sound absorbing part 6a is made of an insulating material, and a pair of electrode plates 7 and 8 are arranged inside a box-shaped casing 6b whose one surface is an opening surface so as to face each other with a gap in a direction orthogonal to the opening surface. For example, a PET (polyethylene terephthalate) film 9, which is flexible against sound waves, is uniformly adhered to the surface of the electrode plate 7 on the opening side. The one electrode plate 7 and the PET film 9 are provided so as to close the opening surface of the casing 6b, and the electrode plate 7 and the PET film 9 integrally vibrate in the opposite direction of the electrode plates 7 and 8. It is free. Also, the casing 6b
The ENC fluid composition 1 is provided between the pair of electrode plates 7 and 8 inside.
0 is housed in a sealed state.

In the above ENC fluid composition 10, as shown in FIG. 3, EA particles 12 are uniformly dispersed in an electrically insulating medium 11. The EA particles 12 include a core body 13 made of an organic polymer compound and an electric field aligning inorganic substance (Ele).
The abbreviated ctric inorganic material is hereinafter abbreviated as “EA inorganic material”) and is formed by the surface layer 15 composed of particles 14 to form inorganic / organic composite particles. In this embodiment, the electrically insulating medium 11
Is colorless and transparent silicone oil, the organic polymer compound forming the core 13 of the inorganic / organic composite particles is a polyacrylic acid ester, and the EA inorganic particle 14 forming the surface layer 15 is an inorganic ion exchanger. In addition, it is white titanium hydroxide that is an electric semiconductor inorganic substance. The color of the EA particles (inorganic / organic composite particles) is, for example, white. The ratio of the EA particles 12 contained in the electrically insulating medium 11 is, for example, 7.5% by weight.

Further, as shown in FIG. 2, a pair of electrode plates 7,
Between the eight, a switch 21 as a voltage application adjusting means 20 and a variable power source 22 capable of variably setting the voltage are connected to the electric cable 2.
3 are connected.

Next, the sound absorption by the sound absorbing portion 6a will be described. As shown in FIG. 4, when no voltage is applied between the pair of electrode plates 7 and 8, the ENC fluid composition 10
EA particles 12 are randomly suspended and dispersed in the electrically insulating medium 11. And a pair of electrode plates 7,
When a voltage is applied to 8, as shown in FIG. 5, the EA particles 12 in the ENC fluid composition 10 are arranged and linked in a chain to form a chain (particle chain) 25. Arrange in parallel to the electric field direction.

In this state, when a sound wave (air vibration) 30 is made incident on one of the electrode plates 7, (a), (b) of FIG.
The states of (c) and (d) occur sequentially, and the electrode plate 7 integrally vibrates in the opposite direction of the electrode plates 7 and 8 together with the PET film 9, but the chain 25 itself has an elastic property. As shown in FIG. 6B, the chain 25
When compressed, it bends into a dogleg shape, for example, to generate a repulsive force, and when pulled backward, as shown in FIG. 6D, the chain-like bodies 25 face each other. The EA particles 12 attract each other to generate an attractive force. This makes E
The movement of the chain body 25 in the NC fluid composition 10 causes viscous resistance, resulting in loss (dissipation) of energy of the sound wave 30.

The tension and compression of the chain 25 are repeated with the vibration of the electrode plate 7,
As a result, the chain 25 itself also vibrates. That is, the ENC fluid composition 10 including the chain 25 and the electrode plate structure composed of the electrode film 7 and the PET film 9 resonate with the sound wave 30 incident on the electrode plate 7. The sound wave frequency that gives vibration to the chain 25 is determined by the characteristic frequency of the chain 25, and when a sound wave 30 having a frequency matching the characteristic frequency enters the electrode plate 7,
As shown by arrows A and B in FIG. 7, the chain 25 resonates to absorb the sound wave 30, and the sound wave 31 of another frequency is reflected.

Since the force acting on each EA particle 12 (stress generated in the chain 25) increases as the voltage applied between the pair of electrode plates 7 and 8 increases, the chain 25 itself is The elastic modulus and viscosity increase as the applied voltage increases. The present invention utilizes this fact to remove a desired component of a sound wave. That is, by adjusting the applied voltage to match the characteristic frequency of the chain 25 itself with the frequency of the component (sound wave having a specific wavelength) to be removed in the sound wave (air vibration) incident on the electrode plate 7, As shown in FIG. 7, the chain 25 is moved by the action of inertial force to the left and right arrows A, B.
Resonates as shown by (1), consumes the energy of the component of the incident sound wave 30 that is desired to be removed, and reflects the other sound wave component (denoted by reference numeral 31). in this way,
The applied voltage can absorb a desired specific wavelength component of the incident sound wave.

The applied voltage is set by adjusting the applied voltage by the variable power source 22 when the air supply duct 2 is installed or when the frequency distribution of noise changes due to changes in usage conditions. Then, the characteristic frequency of the chain 25 itself can be matched with the frequency component of noise.
At this time, the chain 25 resonates with the sound wave of the frequency component of the noise, consumes the energy of the sound wave having the frequency component, and the noise is absorbed.

From the above, in the air supply duct 2, with respect to the noise of the air supply duct 2 whose frequency distribution differs depending on the installation condition and the use condition, the voltage is adjusted in accordance with the range of the noise actually observed. By adjusting the application adjusting means 20, the sound absorption band of the sound absorbing plate 6 can be selected, the sound waves in the sound range can be efficiently absorbed, and the noise reduction of the air supply duct 2 can be achieved.

At this time, when setting the sound absorbing band of the sound absorbing plate 6, it is preferable to set the sound absorbing bands of the sound absorbing parts 6a, 6a ... individually so that the noise can be optimally reduced as a whole. When the frequency distribution of noise is narrow, even if the sound absorption bands of all the sound absorbing parts 6a, 6a ... Are collectively set to the same frequency band, a noise reduction effect that is practically sufficient can be obtained.

Further, a sensor for detecting the frequency distribution of noise is arranged, and each sound absorbing unit 6 is responsive to a signal from this sensor.
If the method of automatically controlling the applied voltage of a, 6a ...
It is possible to deal with the case where the rotation frequency of the fan driving motor connected to the air supply duct 2 is controlled by an inverter and the frequency distribution of noise changes sequentially, which is a more preferable embodiment.

By the way, the characteristic frequency of the sound wave to be absorbed is
The size of the EA particles 12, the elastic force acting between the EA particles 12,
It also changes depending on the natural frequency of the electrode plate 7 and the distance between the electrode plates 7 and 8. In this embodiment, the electrically insulating medium 11
Since the spherical EA particles 12 having a substantially uniform particle size are dispersed therein (without using irregular particles), the above-mentioned repulsive force and attractive force do not fluctuate under a constant voltage, and EA
The balance between the elastic force acting between the particles 12 and the inertial force of the electrode plate 7 hardly changes. In the above-mentioned embodiment, the chain body is supposed to be bent in a V shape, but in addition to this,
For example, an S-shape as shown in FIG.
It is considered that there is a case where it is bent into a W-shape as shown in (b).

Further, in the above-mentioned embodiment, the phenomenon in which the EA particles (inorganic / organic composite particles) 12 form one row of chain-like bodies 25 and are arranged in parallel by the application of a voltage has been described. If the number of the chains exceeds 25% by weight, the chains 25 are not joined in one row but a plurality of rows are joined to each other to form a column 26 as shown in FIG. Come to do. In this column 26, the left and right chain-shaped EA particles 12 are staggered one by one and adjoin each other. With respect to this, the inventors of the present invention, as shown in (b) of FIG. 9, have an EA that is dielectrically polarized in the + pole portion and the − pole portion.
It is presumed that this is because it is more stable in terms of energy when the particles 12 are alternately adjacent to each other and the + pole portion and the − pole portion are arranged so as to attract each other. Furthermore, although the ENC fluid composition 10 is housed between the pair of electrode plates 7 and 8 in the above-mentioned embodiment, the ENC fluid composition 10 is not limited to this.
The porous body sufficiently impregnated with may be housed between the pair of electrode plates 7 and 8. In this case, the porous body preferably has open cells so as not to impair the EA effect.

The electrically insulating medium 11 used in the ENC fluid composition 10 of the present invention includes, for example, diphenyl chloride, butyl sebacate, aromatic polycarboxylic acid higher alcohol ester, halophenyl alkyl ether, trans oil, and chloride. Any fluid such as paraffin, fluorine-based oil, silicone-based oil, fluorosilicone-based oil, etc., as long as it has high electric insulation and electric breakdown strength, is chemically stable, and can stably disperse EA particles or Mixtures of these can also be used. The electrically insulating medium 11 can be colored according to the purpose. For coloring, it is preferable to use a type and amount of an oil-soluble dye or a dispersible dye that is soluble in the selected electrically insulating medium and does not impair its electrical properties. The electrically insulating medium 11 may further contain a dispersant, a surfactant, a viscosity modifier, an antioxidant, a stabilizer and the like.

The kinematic viscosity of this electrically insulating medium 11 is 1c.
It is preferably in the range of St to 30,000 cSt. When the kinematic viscosity is less than 1 cSt, the storage stability of the ENC fluid composition 10 is insufficient, and the kinematic viscosity is 300.
If it is larger than 00 cSt, it is difficult to uniformly disperse the EA particles 12, and bubbles are entangled during the adjustment, which makes it difficult to remove the bubbles, which is unfavorable in handling. From this viewpoint, the kinematic viscosity is from 10 cSt to 100.
Within the range of 0 cSt, especially 10 cSt to 100 cSt
It is preferably within the range. Of course, the kinematic viscosity of the electrically insulating medium 11 changes with temperature, and this temperature effect can be suppressed by the applied voltage.

The EA particles 12 used in the present invention are EA particles.
Any material such as an element, an organic compound, an inorganic compound, or a mixture thereof can be used as long as it is an inorganic / organic composite particle having an effect. Examples thereof include particles of inorganic ion exchangers, metal oxides, silica gel, inorganic substances having electric semiconductors, carbon black, and particles having these as a surface layer.
However, the EA particles 12 are inorganic-organic composite particles formed by the core body 13 made of an organic polymer compound and the surface layer 15 made of the EA inorganic particles 14 as shown in the above-mentioned examples. Is particularly preferable. This inorganic
Organic composite particles are EA inorganic particles 1 having a relatively high specific gravity.
The surface layer 15 composed of 4 is carried on the core body 13 which is an organic polymer compound having a relatively low specific gravity, and the specific gravity of the whole particles can be adjusted so as to approximate to the electrical insulating medium 11. Therefore, the ENC fluid composition obtained by dispersing this in the electrically insulating medium 11 has excellent storage stability.

Examples of the organic polymer compound that can be used as the core body 13 of the EA particles (inorganic / organic composite particles) 12 are poly (meth) acrylic acid ester, (meth) acrylic acid ester-styrene copolymer, polystyrene. , Polyethylene, polypropylene, nitrile rubber, butyl rubber, A
Examples include BS resins, nylon, polyvinyl butyrate, ionomers, ethylene-vinyl acetate copolymers, vinyl acetate resins, polycarbonate resins, and the like, or a mixture or copolymer of two or more kinds.

Various particles can be used as the particles 14 which are the EA inorganic material forming the surface layer 15, and preferred examples include an inorganic ion exchanger, silica gel and an electrically semiconductive inorganic material. When these particles 14 are used to form the surface layer 15 on the core body 13 made of an organic polymer compound, the obtained inorganic / organic composite particles are useful EA.
It becomes particles 12.

Examples of the above-mentioned inorganic ion exchanger include (1)
Hydroxide of polyvalent metal, (2) hydrotalcites,
(3) Acid salt of polyvalent metal, (4) Hydroxyapatite, (5) Nasicon type compound, (6) Clay mineral, (7)
Mention may be made of potassium titanates, (8) heteropolyacid salts, and (9) insoluble ferrocyanide.

The respective inorganic ion exchangers will be described in detail below. (1) Hydroxide of polyvalent metal. These compounds are represented by the general formula MO _x (OH) _y (M is a polyvalent metal, x is a number of 0 or more, and y is a positive number), and examples thereof include titanium hydroxide and hydroxide. zirconium,
Examples include bismuth hydroxide, tin hydroxide, lead hydroxide, aluminum hydroxide, tantalum hydroxide, niobium hydroxide, molybdenum hydroxide, magnesium hydroxide, manganese hydroxide, and iron hydroxide. Here, for example, titanium hydroxide refers to hydrous titanium oxide (also known as metatitanic acid or β-titanic acid, Ti
It contains both O (OH) ₂ ) and titanium hydroxide (also known as orthotitanic acid or α-titanic acid, Ti (OH) ₄ ), and the same applies to other compounds.

(2) Hydrotalcites. These compounds have the general formula M ₁₃ Al ₆ (OH) ₄₃ (C
O) ₃ · 12H ₂ O (M is a divalent metal), and the divalent metal M is, for example, Mg, Ca or Ni. (3) Acid salt of polyvalent metal. These are, for example, titanium phosphate, zirconium phosphate, tin phosphate, cerium phosphate, chromium phosphate, zirconium arsenate, titanium arsenate, tin arsenate, cerium arsenate, titanium antimonate, tin antimonate, tantalum antimonate. , Niobium antimonate, zirconium tungstate, titanium vanadate, zirconium molybdate, titanium selenate, and tin molybdate.

(4) Hydroxyapatite. These are, for example, calcium apatite, lead apatite,
Examples include strontium apatite and cadmium apatite. (5) Nasicon type compound. These include, for example, (H ₃ O) Zr ₂ (PO ₄ ) ₃ but in the present invention, a Nasicon type compound in which H ₃ O is replaced with Na can also be used. (6) Clay mineral. These are, for example, montmorillonite, sepiolite, bentonite and the like, with sepiolite being particularly preferred.

(7) Potassium titanates. These general formula _{aK 2 O · bTiO 2 · nH} 2 O (a 0
<A is a positive number that satisfies a ≦ 1, b is a positive number that satisfies 1 ≦ b ≦ 6, and n is a positive number), for example, K ₂ ·
TiO ₂ · 2H ₂ O, K ₂ O · 2TiO ₂ · 2H ₂ O, 0.
5K ₂ O ・ TiO ₂・ 2H ₂ O, and K ₂ O ・ 2.5Ti
For example, O ₂ · 2H ₂ O. Among the above compounds, a
Alternatively, a compound in which b is not an integer is easily synthesized by treating a compound in which a or b is an appropriate integer with an acid and substituting K with H.

(8) Heteropolyacid salt. These are represented by the general formula H ₃ AE ₁₂ O ₄₀ .nH ₂ O (A is phosphorus, arsenic, germanium, or silicon, E is molybdenum, tungsten, or vanadium, and n is a positive number), For example, ammonium molybdophosphate and ammonium tungstophosphate. (9) Insoluble ferrocyanide. These are compounds represented by the following general formula. M _b -pxa
A [E (CN) ₆ ] (M is an alkali metal or hydrogen ion, A is a heavy metal ion such as zinc, copper, nickel, cobalt, manganese, cadmium, iron (III) or titanium, E is iron (II), iron (III), cobalt (II) or the like, b is 4 or 3, a is a valence of A, and p is a positive number of 0 to b / a.) These include, for example, Cs. Insoluble ferrocyanine compounds such as ₂ Zn [Fe (CN) ₆ ] and K ₂ Co [Fe (CN) ₆ ] are included.

The inorganic ion exchangers (1) to (6) each have an OH group, and some or all of the ions present at the ion exchange sites of these inorganic ion exchangers are replaced with other ions. Those substituted with (hereinafter, referred to as a substitutional inorganic ion exchanger) are also included in the inorganic ion exchanger of the present invention. That, R-M ¹ inorganic ion exchanger described above (M ¹ represents an ion species of the ion exchange sites) is expressed as a part or all of M ¹ in the R-M ^1, the ion exchange reaction below A substituted inorganic ion exchanger in which an ionic species M ² different from M ¹ is substituted by
It is an inorganic ion exchanger in the present invention. ^{xR-M 1 + yM 2 →} R x - (M 2) y + xM 1 ( Here x, y respectively represent the valence of ionic species M ^2, M ^1). M ¹ varies depending on the type of the inorganic ion exchanger having an OH group, but when the inorganic ion exchanger exhibits a cation exchange property, M ¹ is generally H ⁺ , and in this case, M ² is an alkali metal or an alkali. Any metal ion other than H ⁺ , such as earth metals, polyvalent typical metals, transition metals or rare earth metals. When the inorganic ion exchanger having an OH group exhibits anion exchange property, M ¹ is generally OH.
^- , In which case M ² is, for example, I, Cl, SCN, N
Any of anions other than OH ⁻ such as O ₂ , Br, F, CH ₃ COO, SO ₄ or CrO ₄ and complex ions.

Further, regarding the inorganic ion exchanger which has once lost the OH group due to the high temperature heat treatment but becomes to have the OH group again by an operation such as immersion in water, the inorganic ion after the high temperature heat treatment is used. Exchangers and the like are also a kind of inorganic ion exchangers that can be used in the present invention, and specific examples thereof include a Nasicon type compound such as (H ₃ O) Zr ₂
(PO ₄₎ HZr ₂ obtained by heating ₃ (PO _{4) 3} and high-temperature heat treatment of hydrotalcite (500 to 700
Heat treatment at ℃) etc. These inorganic ion exchangers can be used not only in one kind but also in many kinds simultaneously as a surface layer. It is particularly preferable to use a hydroxide of a polyvalent metal and an acid salt of a polyvalent metal as the above inorganic ion exchanger.

EA particles (inorganic / organic composite particles) 12
An example of the electrically semiconducting inorganic material that can be used as the surface layer 15 of is an electric conductivity of 10 ³ to 10 ^-11 Ω ^-1 / cm at room temperature.
Metal oxides, metal hydroxides, metal oxide hydroxides, inorganic ion exchangers, or metal-doped ones of at least one of these, or at least any one of them regardless of the presence or absence of metal doping. For example, the seed is applied to another support as an electric semiconductor layer.

Examples of preferable electrically semiconductive inorganic substances are shown below. (A) Metal oxide: For example, SnO ₂ or amorphous titanium dioxide (manufactured by Idemitsu Petrochemical Co., Ltd.). (B) Metal hydroxide: For example, titanium hydroxide or niobium hydroxide. Here, titanium hydroxide means hydrous titanium oxide (manufactured by Ishihara Sangyo Co., Ltd.), metatitanic acid (also known as β-titanic acid, TiO (OH)).
₂ ) and orthotitanic acid (also known as α-titanic acid, Ti (O
H) ₄ ) is included. (C) Metal oxide hydroxide: For example, FeO
(OH) (goethite) and the like can be mentioned. (D) Hydroxide of polyvalent metal: equivalent to inorganic ion exchanger (1). (E) Hydrotalcites: Inorganic ion exchanger (2)
Equivalent to (F) Acid salt of polyvalent metal: equivalent to the inorganic ion exchanger (3). (G) Hydroxyapatite: Inorganic ion exchanger (4)
Equivalent to (H) Nashicon type compound: equivalent to the inorganic ion exchanger (5). (I) Clay mineral: equivalent to the inorganic ion exchanger (6). (J) Potassium titanate: equivalent to the inorganic ion exchanger (7). (K) Heteropolyacid salt: equivalent to the inorganic ion exchanger (8). (L) Insoluble ferrocyanide: equivalent to inorganic ion exchanger (9). (M) Metal-doped EA inorganic substance: This is obtained by doping the EA inorganic substance with a metal such as antimony (Sb) in order to increase the electric conductivity of the above-mentioned electric semiconductor inorganic substances (A) to (L). For example, antimony (S
b) Doping tin oxide (SnO ₂ ) and the like can be mentioned. (N) EA inorganic material applied as an electric semiconductor layer on another support: for example, titanium oxide, silica as a support,
Examples thereof include inorganic particles such as alumina and silica-alumina, or organic polymer particles such as polyethylene and polypropylene, to which antimony (Sb) -doped tin oxide (SnO ₂ ) is applied as an electric semiconductor layer. . The particles in which the EA inorganic substance is applied to the other support as described above can be regarded as the EA inorganic substance as a whole. These EA minerals are not only one type, but two
It is also possible to use types or more simultaneously as the surface layer.

The EA particles (inorganic / organic composite particles) 12 are
It can be manufactured by various methods. For example, there is a method in which a particulate core body 13 made of an organic polymer compound and fine particulate particles 14 are transported by a jet stream and collided with each other to produce them. In this case, the fine particles of the particles 14 collide with the surface of the particulate core 13 at a high speed and are fixed to form the surface layer 15. As another example of the manufacturing method, there is a method of suspending the particulate core body 13 in a gas, atomizing the solution of the particles 14 and spraying the solution onto the surface thereof. In this case, the solution adheres to the surface of the core body 13 and is dried so that the surface layer 1
5 is formed.

A particularly preferred method for producing the EA particles (inorganic / organic composite particles) 12 is the core layer 13 and the surface layer 15 at the same time.
Is a method of forming. This method is performed by, for example, the core 13
When emulsion-polymerizing, suspension-polymerizing or dispersion-polymerizing a monomer of an organic polymer compound which forms a polymer, particles 14 which are fine particle EA inorganic substances are present in the monomer or in the polymerization medium. Is.
Water is preferred as the polymerization medium, but a mixture of water and a water-soluble organic solvent can also be used, and an organic poor solvent can also be used. According to this method, the monomers are polymerized in the polymerization medium to form the core particles 13, and at the same time, the fine particles of the EA inorganic particles 14 are layered on the surface of the core 13 to coat the core particles 13. The surface layer 15 is formed.

When the EA particles (inorganic / organic composite particles) are produced by emulsion polymerization or suspension polymerization, the EA inorganic particles 14 are combined by combining the hydrophobic property of the monomer and the hydrophilic property of the EA inorganic substance. Can be attached to the surface of the core body 13. This core 13
According to the method for simultaneously forming the surface layer 15 and the surface layer 15, the EA inorganic particles 14 are densely and firmly adhered to the surface of the core body 13 made of an organic polymer compound, and the robust EA particles (inorganic / organic composite particles) 12 are formed. It is formed.

The shape of the EA particles 12 used in the present invention does not necessarily have to be spherical, but the particle-shaped core body 13 is used.
When the EA particles 12 are produced by a controlled emulsion-suspension polymerization method, the resulting EA particles 12 have a substantially spherical shape.
Although the particle size of the EA particles 12 is not particularly limited,
0.1 μm to 500 μm, especially 5 μm to 200
It is preferably within the range of μm. The particle size of the fine particles of EA inorganic particles 14 at this time is not particularly limited, but is preferably 0.005 μm to 100 μm.
μm, more preferably 0.01 μm to 10 μm.

In the EA particles (inorganic / organic composite particles) 12, the weight ratio of the EA inorganic particles 14 forming the surface layer 15 to the organic polymer compound forming the core 13 is not particularly limited. In order to obtain the ENC fluid composition 10 having high storage stability, the particles 14 are added to the total weight of the particles 14 of the EA inorganic material and the core body 13 of the organic polymer compound.
Is preferably in the range of 1% to 60% by weight, particularly preferably in the range of 4% to 30% by weight. When the proportion of the core body 13 is less than 1% by weight, the obtained EA particles 1
When the EA characteristic of 2 becomes insufficient and exceeds 60% by weight,
There is a possibility that the specific gravity of the EA particles 12 becomes excessive and the storage stability is impaired. Further, the ENC fluid composition 10 has the above-mentioned E content.
The A particles 12 can be produced by uniformly stirring and mixing in a electrically insulating medium together with a dispersant and other components if necessary. As the stirrer, any stirrer normally used for dispersing solid particles in a liquid dispersion medium can be used. The content of the EA particles 12 in the electrically insulating medium 11 is not particularly limited, but is preferably 0.5 to 75% by weight, and particularly preferably 5 to 50% by weight. If the content is less than 1% by weight, a sufficient EA effect cannot be obtained,
If it is 75% by weight or more, the initial viscosity of the ENC fluid composition 10 when a voltage is not applied becomes too large, which makes it difficult to use.

Various methods described above, particularly the core body 13 and the surface layer 15
EA particles produced by a method of simultaneously forming and
In No. 2, the whole or a part of the surface layer 15 is covered with a thin film of an organic polymer substance, a dispersant used in the manufacturing process, an emulsifier and other additive substances, and the EA effect as EA particles is not sufficiently exhibited. There are cases. This thin film of inert material can be easily removed by polishing the surface of the particles. Therefore, when the core body 13 and the surface layer 15 are simultaneously formed, it is preferable to polish the surfaces thereof.

The polishing of the particle surface can be performed by various methods. For example, EA, which is an inorganic / organic composite particle
The particles 12 can be dispersed in a dispersion medium such as water, and the mixture can be stirred. At this time, the EA particles 1 are mixed with abrasives such as sand particles and balls in the dispersion medium.
It can also be carried out by a method of stirring together with 2, a method of stirring using a grinding wheel, or the like. For example, again
It is also possible to carry out dry stirring using the EA particles 12 and the above-mentioned abrasive or grinding stone without using the dispersion medium.

A more preferable polishing method is EA particles 12
Is a method of stirring the air flow by a jet air flow or the like.
This is a method of polishing particles by violently colliding with each other in a gas phase, and is a preferable method in that the polished particles can be easily separated by classification without the need for another abrasive. In the above jet stream agitation, it is necessary to select polishing conditions depending on the type of equipment used, the agitation speed, the material of the EA particles 12, etc., but generally 0.5 min to 15 min at a stirring speed of 6000 rpm.
It is preferable to stir with a jet stream.

The ENC fluid composition 10 is the above EA.
The particles 12 can be manufactured by uniformly stirring and mixing the particles 12 in the electrically insulating medium 11 together with other components such as a dispersant. As the stirrer, any stirrer normally used for dispersing solid particles in a liquid dispersion medium can be used.

Although a rectangular air supply duct is used as the air supply duct 2 in the above embodiment, the present invention is not limited to the rectangular air supply duct.
It can be applied to other shapes such as a circle. Also, the sound absorbing plate 6
Can be appropriately divided into the sound absorbing parts 6a, 6a ..., Therefore, it can be applied not only to the straight pipe part but also to various connecting parts such as a branch part and a different diameter connecting part. Further, in the above embodiment, the sound absorbing plates 6, 6 are attached to the inner surfaces of the side wall bodies 3, 3 of the air supply duct 2, but in the present invention, there is no limitation on the attaching position of the sound absorbing plate. Not something to do,
In addition to or instead of the inner surfaces of the side plates 3 and 3, the upper wall body 4 is formed.
Alternatively, it may be attached to the lower wall body 5. Furthermore,
It may be a part of the side wall body 3 instead of the entire surface. The installation of the sound absorbing plate 6 may be set appropriately in consideration of the noise level. Further, in place of the PET (polyethylene terephthalate) film 9 in the above-mentioned examples, various plastic films such as PVC (polyvinyl chloride) film, nylon film, acrylic film and the like, which are flexible to sound waves and which are open surfaces of the casing 6b. Various films having good occluding property can be used.

[0053]

The air supply duct of the present invention has the following effects. Change the sound absorption band of the sound absorbing plate by adjusting the voltage application adjusting means according to the sound range actually observed for the noise of the air supply duct whose frequency distribution differs depending on the installation situation and usage situation Since it is possible to efficiently absorb sound waves in the sound range of noise, a low noise type air supply duct can be obtained. Since only the sound absorbing plate is attached to the inner surface of the tubular wall, it does not hinder the air supply, so it does not reduce the efficiency of air supply, and also the air supply duct becomes large. Absent. Since the sound absorbing plate does not have directionality for air supply,
Since it is not necessary to consider the orientation when constructing the air supply duct, it is possible to obtain an air supply duct having high workability.

[Brief description of drawings]

FIG. 1 shows an embodiment of an air supply duct of the present invention, (a) is a perspective view and (b) is a sectional view.

FIG. 2 is a cross-sectional view showing a main part of the air supply duct.

FIG. 3 is a cross-sectional view showing an example of an ENC fluid composition according to the present invention.

FIG. 4 is a cross-sectional view showing a mode of the ENC fluid composition when the power is turned off.

FIG. 5 is a cross-sectional view showing a mode of the ENC fluid composition when the power is turned on.

FIG. 6 is an explanatory diagram for explaining vibration of one electrode in the sound absorbing plate used in one embodiment of the air supply duct of the present invention.

FIG. 7 is an explanatory diagram showing a resonance mode of the sound absorbing plate.

FIG. 8 is an explanatory diagram showing another resonance mode of the sound absorbing plate.

FIG. 9 is an explanatory diagram showing an arrangement form of EA particles in the sound absorbing plate.

FIG. 10 is a graph showing the results of measuring the effect of electric field strength on EA characteristics of an EA particle dispersion system.

FIG. 11 is an equivalent circuit of vibration in the same EA particle dispersion system.

FIG. 12 is a perspective view showing a conventional example of an air supply duct.

[Explanation of symbols]

2 ... Air supply duct, 2a ... Cylindrical wall body, 6 ... Sound absorbing plate, 7 ... Electrode plate, 8 ... Electrode plate, 10 ... ENC fluid composition, 11 ... Electrical insulating medium, 12 ... EA particles, 20 ... Voltage Application adjusting means.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Reference number within the agency FI Technical indication location G10K 11/16 (72) Inventor Kazuya Edamura 2-6-15 Shiba Koen, Minato-ku, Tokyo Fujikura (72) Inventor Hidenobu Anzai Hidenobu Anzai 1-5-1, Kiba, Koto-ku, Tokyo Fujikura Co., Ltd.

Claims (1)

[Claims] 1. A cylindrical wall body having a sound absorbing plate adhered to an inner surface thereof, the sound absorbing plate being disposed between a pair of opposing electrode plates and an electric field array. A fluid composition for electro-sensitive sound wave absorption control comprising solid particles having an effect in an electrically insulating medium, and a voltage application adjusting means for applying a voltage between the pair of electrode plates and adjusting the voltage. An air supply duct comprising: